--  @testpoint:opengauss关键字preserve(非保留)，作为函数名

--关键字不带引号-成功
drop function if exists preserve;
create function preserve(i integer)
returns integer
as $$
begin
    return i+1;
end;
$$ language plpgsql;
/
drop function preserve;
--关键字带双引号-成功
drop function if exists "preserve";
create function "preserve"(i integer)
returns integer
as $$
begin
    return i+1;
end;
$$ language plpgsql;
/
drop function "preserve";
--关键字带单引号-合理报错
drop function if exists 'preserve';
create function 'preserve'(i integer)
returns integer
as $$
begin
    return i+1;
end;
$$ language plpgsql;
/
--关键字带反引号-合理报错
drop function if exists `preserve`;
create function `preserve`(i integer)
returns integer
as $$
begin
    return i+1;
end;
$$ language plpgsql;
/